India and China have reached an agreement on military disengagement along their disputed border, New Delhi said, a step toward reducing frictions between the nuclear-armed neighbors that comes as both countries’ leaders arrive in Russia for a summit.

Four years ago, several soldiers from both sides were killed in a bloody melee. Any thaw between the countries could have global implications.

The nuclear-armed neighbors have reached a breakthrough in discussions over their disputed Himalayan border, four years after a clash that saw security forces engage in hand-to-hand combat.